// 初期設定（Cookie）
var ckName = "fontSizeChange";
var ckDays = 1;
var ckPath = "/";
var fontCookie = GetCookie(ckName);

// フォントサイズ変更
if ( fontCookie == null ) {
	Size = 100;
} else {
	Size = Number(fontCookie);
}

function fontChange() {
	document.body.style.fontSize = Size + "%";
}

function sizeChange( Chk ){
	if( Chk == "large" ){
		var newSize = 120;
		SetCookie( ckName , newSize );
	}
	if ( Chk == "middle" ){
		var newSize = 100;
		SetCookie( ckName , newSize );
	}
	if ( Chk == "small" ){
		var newSize = 75;
		SetCookie( ckName , newSize );
	}
	// call FontChange Function
	Size = newSize;
	fontChange();
}


// クッキー管理

function SetCookie(name,value){
	var dobj = new Date();
	dobj.setTime( dobj.getTime() + 24 * 60 * 60 * ckDays * 1000);
	var expiryDate = dobj.toGMTString();
	document.cookie = name + '=' + escape(value)+ ';expires=' + expiryDate + ';path=' + ckPath;
}

function SetCookie(name,value){
	var dobj = new Date();
	dobj.setTime( dobj.getTime() + 24 * 60 * 60 * ckDays * 1000);
	var expiryDate = dobj.toGMTString();
	document.cookie = name + '=' + escape(value)+ ';expires=' + expiryDate + ';path=' + ckPath;
}
function GetCookie (name){
	var arg	= name + "=";
	var alen = arg.length;
	var clen = document.cookie.length;
	var i = 0;
	while (i < clen){
		var j = i + alen;
		if (document.cookie.substring(i, j) == arg)
		return getCookieVal (j);
		i = document.cookie.indexOf(" ", i) + 1;
		if (i == 0) break;
	}
	 return null;
}
function getCookieVal (offset){
	var endstr = document.cookie.indexOf (";", offset);
	if (endstr == -1)
	endstr = document.cookie.length;
	return unescape(document.cookie.substring(offset,endstr));
}
function DeleteCookie(name){
	if (GetCookie(name)) {
		document.cookie = name + '=' +
		'; expires=Thu, 01-Jan-70 00:00:01 GMT;path='+ckPath;
	}
}